Bug #74871 [Com]: if statement behavior

Edit report at https://bugs.php.net/bug.php?id=74871&edit=1 ID: 74871 Comment by: spam2 at rhsoft dot net Reported by: johovich at yande dot ru Summary: if statement behavior Status: Not a bug Type: Bug Package: *General Issues Operating System: Linux version 2.6.32-531.23.3.lv PHP Version: 7.1.7 Block user comment: N Private report: N New Comment: and "if($pos = 0)" is always true because = assigns a value while == and === compare a value [harry@srv-rhsoft:/downloads]$ php test.php DO NOT USE A SINGLE = TO COMPARE SOMETHING [harry@srv-rhsoft:/downloads]$ cat test.php <?php if($test = 1) { echo "DO NOT USE A SINGLE = TO COMPARE SOMETHING\n"; } ?> Previous Comments: ------------------------------------------------------------------------ [2017-07-07 00:04:56] rtheunissen@php.net Thank you for taking the time to write to us, but this is not a bug. Please double-check the documentation available at http://www.php.net/manual/ and the instructions on how to report a bug at http://bugs.php.net/how-to-report.php This is expected behaviour, an if statement defaults to a non-strict boolean comparison. ------------------------------------------------------------------------ [2017-07-07 00:01:30] rtheunissen@php.net This is not a bug. if ($condition) is the same as if ($condition == true), so in the second part of your test script if you changed the strict !== to !=, you would get the same results. So you're effectively saying if (($pos = 0) == true) which will drop to the else. ------------------------------------------------------------------------ [2017-07-06 23:51:22] johovich at yande dot ru Description: ------------ If i use set var inside 'if' statement condition $var = '0' is the same as $var = false. But it is not the same. So if assign var to function that returns 0 as integer or 0 as string 'if' statement condition works as false. Test script: --------------- //In this script you can see, that set var value to 0 is equal to boolean false //applied to if statement. There is no diff between integer 0 or string '0' if($pos = 0){ $pos++; } else { $pos = 0; } var_dump($pos); //$pos is not boolean false, so it should do if condition true, but it's not //to make this work well i use this $pos = 0; if($pos !== false){ $pos++; } else { $pos = 0; } var_dump($pos); ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=74871&edit=1